Polymat shingle

ABSTRACT

Disclosed is a shingle that uses a polyester sheet as a substrate layer. The polyester sheet has a sufficient weight and is needled and formed from two layers to resist shrinking upon cooling after the heated asphalt layers are applied to the polyester substrate sheet  102 . In addition, additives may be included in the asphalt to lower the softening point temperature of the asphalt that further reduces shrinking of the polyester substrate  102  or allows other polymers that are more fire retardant to be used. Fire retardants can be placed in the polyester sheet fibers, placed in the bonding agent for the polyester fibers, or the polyester sheet can be coated with the fire retardant. Alternatively, or in addition to treating the polyester sheet  102  with fire retardant, fire retardant materials such as ammonium sulfate can be added to the liquid asphalt prior to application of the asphalt layers.

CROSS-REFERENCE TO RELATED APPLICATION

This Non-Provisional patent application claims the benefit of the Provisional U.S. Patent Application No. 62/628,141, entitled “Polymat Shingle,” which was filed with the U.S. Patent & Trademark Office on Feb. 8, 2018, which is specifically incorporated herein by reference for all that it discloses and teaches.

BACKGROUND OF THE INVENTION

Shingle technology has advanced greatly over the past few decades. Roof shingles provide protection for houses and buildings to prevent leakage of rain water into the interior of the building. Various types of materials have been used to make shingles including asphalt and other materials.

SUMMARY OF THE INVENTION

An embodiment of the present invention may therefore comprise a method of making a roofing shingle comprising: forming a non-woven polyester sheet having a mass of at least 65 grams per square meter; coating the non-woven polyester sheet with a fire retardant; heating asphalt to a liquid state; applying the asphalt in the liquid state to a first side of the polyester sheet and to a second side of the polyester sheet; allowing the asphalt to cool in ambient air.

The present invention may further comprise a method of making an impact resistant roofing shingle comprising: forming a porous polyester sheet having a mass of at least 65 grams per square meter that is made from a plurality of extruded viscoelastic polyester fibers that are entangled using a needle punch process and fused together using heat and pressure; heating asphalt to a liquid state to create liquid asphalt; mixing a fire retardant with the liquid asphalt to form a fire retardant asphalt; applying the fire retardant asphalt to both a top surface and a bottom surface of the porous polyester sheet; applying granules and fines to the fire retardant asphalt to form a shingle material.

The present invention may further comprise a method of making an impact resistant and fire retardant roofing material comprising: mixing polyester and a fire retardant in a dry state; heating the polyester and the fire retardant to form a fire retardant and polyester liquid; extruding the fire retardant polyester liquid to form a plurality of extruded fire retardant polyester fibers; entangling the resulting fire retardant polyester fibers through a needle punch process to create at least one layer of intertwined, non-woven, polyester fibers; calendering the at least one layer of intertwined, non-woven, polyester layer by passing the polyester layer through a heated calender roll to form a porous fire retardant polyester sheet; heating asphalt to a liquid state to create liquid asphalt; applying the liquid asphalt to both a top surface and a bottom surface of the porous, fire retardant polyester sheet; applying granules and fines to the asphalt to form the impact resistant roofing material.

The present invention may further comprise a system for making an impact resistant polyester roofing shingle comprising: a non-woven, two layer polyester sheet that is made from a plurality of extruded polyester fibers that are entangled in a needle punch process and fused together by passing the polyester layer through heated calender rolls to form a porous polyester sheet; a heated asphalt mixer that mixes a fire retardant material with a heated, liquid asphalt to create a fire retardant liquid asphalt; coaters that coat the non-woven, two layer polyester sheet with the fire retardant liquid asphalt on both a top surface and a bottom surface of the non-woven, two layer polyester sheet to form an asphalt coated polyester sheet; a granule applicator that applies granules to the asphalt coated polyester sheet; a fines applicator that applies fines to the asphalt coated polyester sheet.

The present invention may further comprise a system for making an impact resistant polyester roofing shingle material comprising: a mixer that mixes polyester with a fire retardant to form a fire retardant, polyester dry mix; an extruder that heats the fire retardant, polyester dry mix to form a fire retardant, polyester liquid; a metering pump and spinneret system that extrudes the fire retardant, polyester liquid to form a plurality of extruded fire retardant polyester fibers; a needling machine that entangles the fire retardant polyester fibers to create at least one layer of intertwined, non-woven, polyester fibers; a calender roll process that compresses and heats the layer of entangled, non-woven, polyester fibers to form a porous polyester sheet; coaters that coat the porous polyester sheet with liquid asphalt.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view of an embodiment of a shingle of the present invention.

FIG. 2A is an exploded view of the shingle of FIG. 1.

FIG. 2B is an exploded view of a laminated shingle.

FIG. 3 is a flow diagram of one embodiment of a polyester sheet forming process.

FIG. 4 is a schematic block diagram of an embodiment of a shingle forming apparatus.

FIG. 5 illustrates a polymat fabrication system.

FIG. 6 illustrates a shingle making apparatus.

DETAILED DESCRIPTION OF THE EMBODIMENTS

FIG. 1 is a sectional view of a shingle 100 that comprises an embodiment of the present invention. Shingle 100 has a polyester sheet 102, which forms a substrate that is coated with a first asphalt layer 104 on a first side of the polyester sheet 102, and a second asphalt layer 106 on a second side (bottom) of the polyester sheet 102. Granules 103 are placed on the surface of the asphalt layer 104. Fines 105 are placed on the asphalt layer 106. The asphalt layers 104, 106 can be sprayed onto the polyester sheet 102 during formation of the shingle 100. The asphalt in the asphalt layers 104, 106 is heated until the asphalt is in a liquid state so that the asphalt layers 104 and 106 are absorbed into the polyester sheet 102, which is porous. In this manner, the asphalt layers 104, 106 are tightly adhered to the polyester sheet 102.

The polyester sheet 102 provides impact resistance for the shingle. Damage to standard shingles that use fiberglass substrates occurs since the fiberglass is brittle and breaks when impacted by an object such as a hail stone. When the fiberglass substrate is broken the structural integrity of the shingle is compromised. The use of a polyester substrate, which is malleable and can deflect impact stress without breaking, provides a high degree of impact resistance. Of course, a sufficient thickness of non-woven fused polyester sheet material must be used to provide an adequate substrate. In that regard, a thickness of at least 65 grams per square meter must be utilized to provide an adequate non-woven polyester substrate that is capable of providing sufficient impact resistance to maintain the structural integrity of the shingle for impacts normally encountered by shingles. Various patents have addressed the issue of impact resistance, such as U.S. Pat. Nos. 5,571,596, 6,228,785, 6,709,994, 7,442,658, 7,670,668, 8,226,790, 9,010,058, all of which are specifically incorporated herein by reference for all that they disclose and teach. Further, polyester mat substrates have been mentioned in U.S. Patent Publication 2015/0240494 but does not address the manner in which various problems, such as shrinkage, can be overcome. U.S. Pat. No. 6,207,593 discloses an asphalt coated mat and U.S. Pat. No. 4,287,248 discloses a bituminized roof sheet.

In some cases, the polyester sheet 102 may have a tendency to shrink slightly when cooling after the hot liquid asphalt of the asphalt layers 104, 106 is applied to the polyester sheet 102. This can be ameliorated by using a double thickness polyester layer as the polyester sheet 102, as disclosed in greater detail in FIG. 3. In addition, certain additives can be mixed with the asphalt that forms the asphalt layers 104, 106 to lower the equiviscous temperature at which the asphalt must be applied. Of course, the lower the temperature, the less heat that is applied to the polyester sheet 102 and the less shrinkage there is in the polyester sheet 102. In addition, the shingle forming machine, such as illustrated in the block diagram of FIG. 4, is constructed so that the shingles are not subjected to a large pulling force during and after application of the hot asphalt, which can stretch the polyester sheet 102. Accordingly, the shingle forming process, disclosed in FIG. 4, can be designed to minimize the pulling forces used on the polyester sheets 142 after the polyester sheets 142 have been coated with asphalt.

Essentially, the pulling forces can be minimized during and after the application of the asphalt to the polyester sheets by operating the rollers located in the feeder 142 that advances the polyester sheets and the rollers that advance the polyester rolls in the feeder 143 so that they spin slightly faster than the rollers that advance the polyester sheets and/or polyester roll material through the asphalt top coater 144 and the asphalt bottom coater 146, as well as the granule applicator 156 and the fines applicator 160. When operating at high production speeds, there tends to be more pulling and as a result, more stretching of the heated polyester sheets. To ameliorate this problem, operating the rollers and the feeders 142, 143 just slightly faster tends to push the polyester sheets and polyester roll material through the asphalt top coater 144, asphalt bottom coater 146, granule applicator 156 and fines applicator 160, so that there is less pulling of the polyester sheets and, consequently, less lateral shrinkage of the polyester sheets. In addition, and as disclosed below, additives can be used to adjust the softening point temperature, softness and other parameters of the asphalt, so that the asphalt is applied by the asphalt top coater 144 (FIG. 4) and the asphalt bottom coater 146 (FIG. 4) at a lower temperature, which causes less shrinking as a polyester sheet is cooled with the asphalt coating. This is disclosed in more detail below with respect to the description of FIG. 4.

FIG. 2A is an exploded diagram of the shingle 100 of FIG. 1. As illustrated in FIG. 2, the asphalt layer 104 is positioned on one side of the polyester sheet 102, while asphalt layer 106 is positioned on the other side of the polyester sheet 102. Again, the asphalt layers 104, 106 are tightly adhered to the porous polyester sheet 102, since the asphalt layers 104, 106 are applied to the porous polyester sheet 102 in a liquid form, which is absorbed by the polyester sheet 102. After the shingle 100 is formed, the cuts 107 are formed in the assembled shingle.

FIG. 2B is an exploded diagram of a laminated shingle 101. As shown in FIG. 2B, the backer layer consists of an asphalt layer 166, a polyester layer 168 and an asphalt layer 170. In other words, the polyester layer 168 is covered on both the front and the back by asphalt layers 166, 170, respectively. The overlay layer of the laminated shingle 101 consists of an asphalt layer 172, a polyester layer 174 and an asphalt layer 176. Polyester layer 174 is therefore covered on both sides by asphalt layer 172 and asphalt layer 176.

FIG. 3 is a schematic block diagram of the process 107 for forming the polyester sheets that are used in the shingle 100. As illustrated in FIG. 3, polyester chips 108 as well as a fire retardant 109, are heated and mixed at step 110. In this manner, the polyester is combined with the fire retardant 109 prior to being extruded at step 112. Another fire retardant material is Cel-Span FR 789. Cel-Span FR 789 chips are available from Phoenix Plastics of Houston, Tex. Cel-Span FR 789 is a flame retardant concentrate specifically designed and tailored for polyester fibers. Thermoplastic polyester fibers produced from Cel-Span FR 789 and converted into needle punch fabric meet both NPFA 702 vertical burn testing, and at lower levels, horizontal burn testing. The Cel-Span FR 789 concentrate is designed to be compounded directly with SSP polyester fiber chips to produce fine denier fibers. To create the polyester fibers that include the Cel-Span FR 789, the polyester chips are placed in a drying container in which the chips are subjected to a temperature of approximately 140 degrees C. for about eight hours. This causes the chips to be recrystallized and moisture removed from the chips. The polyester chips that have been recrystallized are then fed into a cylinder together in the correct proportion with the Cel-Span FR 789 chips and moved down the cylinder with an auger to uniformly mix the Cel-Span and polyester chips. The Cel-Span FR 789 can constitute approximately 5% to 20% of the weight of the combined polyester and Cel-Span mixture. The combined chips are then fed into a hopper, which melts the Cel-Span FR 789 and polyester chips, which are then immediately extruded by multiple extrusion dies which comprise a spinneret. The Cel-Span is a light product with low viscosity. The Cel-Span and polymer, when melted, combine at a molecular level and the combination is extruded through the spinneret to form continuous fibers that include both the Cel-Span FR 789 fire retardant and the polyester. In other words, the Cel-Span fire retardant chips are dry mixed with the polyester chips by feeding the respective amounts of polyester chips and Cel-Span chips into the cylinder with an auger, which mixes these chips at the desired ratios prior to feeding the dry mixed chips to a hopper, which melts the Cel-Span chips and polyester chips just prior to extrusion.

Referring again to FIG. 3, at step 112 the mixed polyester and fire retardant are extruded to form a series of fibers that are very thin, i.e., on the order of the thickness of a thread or a strand of hair having a denier of approximately 1.5 to 3.5. These polyester fibers are then cooled at step 114. The fibers form a layer, which is then needled by pre-needler 126. The process of needling is a process in which a large number of needles with oriented barbs are pushed through the thickness of the layer of fibers such that the fibers are hooked by the barbs on the needles and pushed through the adjacent fibrous layer. This causes the layer of fibers to become entangled so that the layer becomes more stable.

As also disclosed in FIG. 3, polyester chips 118 and a fire retardant 119 are heated and mixed together at step 120. When a uniform mixture is obtained, the heated polyester and fire retardant are extruded at step 122 to form a multiplicity of small fibers. The fire retardant 119 is the same fire retardant as fire retardant 109. Again, the polyester chips may already have a fire retardant mixed into the chips. The heating at step 120 occurs approximately simultaneously as the heating at step 110. Each of the steps 120, 122, 124, can occur approximately simultaneously with steps 110, 112, 114, respectively. The heated polyester and fire retardant are extruded at step 122 and cooled at step 124. The layer of polyester fibers is then needled at step 126. A final needling step can occur by final needler 127, in which the two needled polyester fiber layers are brought together in close proximity, and needles with oriented barbs are driven through both layers to further intertwine the two separate layers. The final needler 127 is optional and can be performed in addition to the needling performed by pre-needler 126. The two needled layers of polyester fibers are then calendered at step 128. The calendering is a process in which the two layers of needled fibers of polyester are placed on top of one another and fed through heated rollers that both heat and press the fibrous layers together so that the fibrous layers fuse and form a single, double thickness, polyester sheet. The bonding can occur by using a bonding agent 127 and/or bonding by fusing the polyester fibers through the application of heat.

The bonding agent 127 is normally applied with the fire retardant at step 132. The bonding agent 127 assists in bonding the fibrous layers to form the single polyester sheet. The bonding agent 127 may comprise an acrylic resin binder that may include a fire retardant binding agent that protects the filaments and reduces shrinking such as SBS 934, which is a melamine solution, available from Royal Adhesive of Simpsonville, South Carolina, or Astromel NW 3A, available from Hexion, Inc. of Columbus, Ohio. The single polyester sheet is then cooled at step 130. A separate application of fire retardant can optionally be applied at step 132. Step 132 is an optional step in which fire retardant such as SVEE 76 from Royal Adhesive, of Simpsonville, S.C., is applied to the polyester sheet by spraying the fire retardant on to the polyester sheet or moving the polyester sheet through a bath. The polyester sheet is then dried at step 134 and cut at step 136. The polyester sheets can then be cut into the size of a shingle, such as shingle 100 and then stacked at step 138. Since the polyester sheets 102 are cut into the size of a shingle, there is less shrinkage because of the smaller size of the polyester sheet 102. Alternatively, the large sheets of polyester can simply be rolled up into large rolls at step 135 after drying at step 134. The large rolls can then be used with the shingle forming apparatus 140, illustrated in FIG. 4.

FIG. 3 discloses two layers of polyester fibers that are needled and joined together. Of course, three layers or any number of layers, can be joined together to increase the strength of the resultant polyester sheet, which also reduces shrinking of the polyester sheet after asphalt is applied to the polyester sheet and cooled, as disclosed below in FIG. 4. In addition, various types of polymers and mixtures of polymers from the polyester family such as polyethylene terephthalate, polybutylene terephthalate, poly-1,4-cyclohexane dimethylene terephthalate etc. Other high temperature performance polymers such as polyimide, polyamide can be used in the different layers that are joined together to form the resultant sheet. The choice of materials can both strengthen the resultant sheet that is used as a shingle substrate and reduce shrinking during the cooling process after the hot asphalt is applied and allowed to cool on the substrate sheet.

FIG. 4 is a schematic block diagram illustrating a shingle forming apparatus 140. As illustrated in FIG. 4, the stacked polyester sheets 142 are fed to an asphalt top coater 144, which coats an asphalt layer 104 on a first side, or top side, of the polyester sheets 142. Alternatively, the large polyester rolls 143 that are created as part of the rolling process 135 of FIG. 3, can be coated with asphalt by the asphalt top coater 144. Asphalt 150 plus optional additives 152 and an optional fire retardant 154 are placed in a heated asphalt vat and mixer 148. The vat and mixer 148 heats the asphalt to a liquid state and blends the asphalt with optional additives 152 and optional fire retardant 154. The fire retardant 154 may comprise ammonium sulfate, as disclosed in U.S. Pat. No. 5,102,463, which is specifically incorporated herein, by reference, for all that it discloses and teaches. Other materials can also be used, such as monoammonium phosphate, as disclosed in U.S. Pat. No. 4,804,696, and potassium citrate, such as disclosed in U.S. Pat. No. 5,026,747. Fire retardant roofing is also disclosed in U.S. Pat. Nos. 8,802,215, 9,441,140, 9,580,902, U.S. Patent Publication 2015/0218823 and U.S. Patent Publication 2017/0067257, U.S. Pat. Nos. 9,242,432, 9,447,581 and U.S Patent Publication 2014/0272244. All of these patents and U.S. patent publications are specifically incorporated herein, by reference, for all that they disclose and teach.

The additives 152 are used to adjust the softening point temperature, softness and other parameters of the asphalt 150. The additives may include the additives disclosed in U.S. Pat. No. 9,598,610 issued Mar. 21, 2017 to Hilsenbeck entitled “Asphalt Upgrading Without Oxidation” which is specifically incorporated herein for all that it discloses and teaches. For example, various waxes as well as napthenic oils, and other compounds, can be added to the asphalt to lower the softening point temperature so that the asphalt and the heated asphalt vat and mixer can be melted at a lower temperature which reduces the amount of shrinking of the polyester sheets 142 when the coated polyester sheets 142 are cooled.

Warm Mix Asphalt (WMA) is a specialty technology which is directed to reduction of the temperatures at which the asphalt softening point temperature and viscosity are reduced. The addition of certain waxes such as Sasobit, which is a Fisher-Tropsch paraffin wax, and Asphaltan B, which is a low molecular weight, esterified wax, can be used to reduce softening point temperature and viscosity. Also, synthetic zeolite sold under the trade name Aspha-Min, and two component binder systems, such as WAM-Foam is a soft binder and a hard foam binder that is added at different stages during the production of the asphalt. An asphalt emulsion product called Evotherm uses chemical additive technology and a dispersed asphalt technology delivery system. These technologies reduce the viscosity of the asphalt binder at given temperatures. Aspha-Min is available from Eurovia Services GmbH, Bottrop, Germany. WAM-Foam is available from Shell International Petroleum Company Ltd., London, UK and Kolo-Veidekke, Oslo, Norway. Sasobit is available from various suppliers including Sasol Ltd., located in Johannesburg, South Africa. Evotherm is a product developed by MeadWestvaco Asphalt Innovations, Charleston, S.C. Advera WMA is available from PQ Corporation, Malvern, Pa. Asphaltan B is a product available from Romonta GmbH, Amsdorf, Germany. In addition, it should be noted that different asphalts have different viscosity profiles and an asphalt having a lower temperature for a given viscosity can be selected to produce these shingles. In addition, oxidizing technologies can be used with the asphalt to lower the viscosity of the asphalt for a given temperature. It is also possible to use other polymer filaments with lower melting temperatures, assuming that the asphalt softening temperature can be sufficiently reduced, such as polyolefin and polypropylene. Other polymers can also be used to form a substrate that is fire retardant.

As also shown in FIG. 4, granule applicator 156 coats the top asphalt layer with granules from granule bin 158. Fines applicator 160 coats the bottom asphalt layer with fines from fine bin 162. After the granules and fines have been applied to the asphalt coating on the polyester sheets 142 or polyester rolls 143, the coated polyester sheets are sent to a stacker 164. The coated rolls are sent to a cutter which cuts the sheets into shingles. The shingles from the fines applicator 160 and cutter 166 are stacked in stacker 164. The stacked shingles can then be shipped to a location for installation.

FIG. 5 illustrates a polymat fabrication system 500. As shown in FIG. 5, a hopper 502 contains polyester chips 506 or chips of another suitable polymer, which are dispersed from the hopper 502 in a metered fashion so that a predetermined amount of the polyester chips 506 are dispersed into the cylinder 512 each minute. Similarly, hopper 504 disperses fire retardant chips 508, such as the Cel-Span FR 789 chips disclosed above. The fire retardant chips 508 are dispersed at a predetermined rate so that the fire retardant chips 508 make up 5%-20% of the mixture of polyester chips 506 and fire retardant chips 508. Auger/mixer 510 mixes the polyester chips 506 and the fire retardant chips 508 together and moves the mixture down the cylinder 512 until the chips are thoroughly mixed. At the end of the cylinder 512 the mixed polyester and fire retardant chips 514 are deposited into a hopper 516. The hopper 516 feeds the mixed polyester and fire retardant chips of 514 into extruder 518. The extruder 518 includes a heater 520 that melts the dry mixed polyester and fire retardant chips 514 until the mixed polyester and fire retardant chips 514 are melted and create a liquid mix of polyester and fire retardant materials. Of course, the fire retardant chips 508 may comprise the Cel-Span FR 789. The liquid mixture of polyester and fire retardant is then pumped by a high pressure pump 522 into the spinneret 524. The spinneret 524 extrudes very fine fibers 526, 528. The fibers or filaments 526 are deposited in a vacuum venturi tube 530, which draws the fibers 536 downwardly through the vacuum venturi tube 530, which also stretches the fibers 536 and adds to their strength and durability. Similarly, fibers 528 are fed into the vacuum venturi tube 532 and are drawn through the vacuum venturi tube 532 and stretched. The fibers 526 exit the vacuum venturi tube 530 and are deposited in a disperser 534. The disperser 534 spreads the fibers across the web forming surface 542 in a substantially even layer to form a first web layer 538. Similarly, fibers 528 are spread by the disperser 536 in a substantially even layer over the first web layer 538 to form a second web layer 540. The two layers are then moved by the web forming surface 542 to needlers 544. The needlers 544 entangle the fibers of the first web layer 538 and the second web layer 540. The entangled webs are then passed through calender rollers 546, which heat and fuse the fibers in the entangled web layers. The calender rollers 546 fuse the fibers together to form a polyester/fire retardant mat, which then proceeds to an optional bonding agent applicator 548. The bonding agent applicator 548 can provide additional bonding to secure and consolidate the resultant fire retardant polyester mat. In addition, a fire retardant applicator 550 can be used to coat the polyester fire retardant mat with additional fire retardant material. As disclosed above, a fire retardant, such as SVEE 76 from Royal Adhesives of Simpsonville, S.C., can be used by spraying the fire retardant on the polyester sheet or, alternatively, moving the polyester sheet through a bath of the SVEE 76. The mat is then sent to a dryer 552 that dries the bonding agent and fire retardant on the mat. The mat can then proceed to a cutter 556 and be cut into individual polyester sheets 558 and deposited in stacker 560, or be rolled into a polyester mat roll 554. The polyester mat roll 554 and the polyester sheets 558 can be used in a shingle making process. The polyester mat roll 554 can also be used for sheet roofing.

FIG. 6 discloses a shingle making apparatus 600. As illustrated in FIG. 6, a polyester roll 602 provides a polyester sheet 604. Polyester roll 602 may comprise a roll, such as polyester mat roll 554 of FIG. 5, that contains fire retardant materials. For purposes of FIG. 6, however, it will be referred to as a polyester sheet 604. The polyester sheet 604 is directed to a top coater 614 and a bottom coater 616, which coat the polyester sheet with asphalt. Asphalt 608 is heated to a liquid state in heater/mixer 606. Other additives 610 are also provided to the heater/mixer 606. These additives may comprise various waxes, as disclosed above. The additives can be used to lower the softening point of the asphalt and allow for the use of other polymer materials other than polyester, as disclosed above, which have greater fire resistance. In addition, fire retardant 612 can also be provided to the heater/mixer 606. As indicated above, the fire retardant may comprise ammonium sulfate, monoammonium phosphate, potassium citrate or other suitable fire retardant materials. The treated asphalt is then applied to both sides of the polymer sheet 604. In some embodiments, the treated asphalt may only be applied to one side of the polymer sheet 604, such as for the fabrication of membranes used to protect foundations and flat roofs.

As further shown in FIG. 6, the sheet moves to the right and granule bin 618 provides granules to a granule applicator 620 that coats certain parts of the shingle or all of the sheet roofing with granules. The sheet then moves to the S rollers 621 so that fines from fine bin 622 can be dispersed by fines applicator 624 on the back side of the roofing material. The sheet then moves to a cutter 626 and is cut into shingles and stored in stacker 628, or is rolled onto sheet roofing roll 630.

The present invention therefore provides a shingle that uses a polyester sheet 100 that is coated with asphalt layers on each side. The polyester sheet 102 has high impact resistance, since impacts to the shingle 100 are absorbed by the polyester sheet 102 that is more malleable than a standard fiber glass substrate. Fiber glass substrates tend to be brittle and break when impacted, such as impacts from hail storms. Fire retardant can be placed in the fibers of the polyester sheet 102 or the polyester sheet can be bonded with a bonding agent that includes a fire retardant. In addition, fire retardant can be applied to the finished polyester sheet 102. Fire retardant can also be mixed with the asphalt that is applied as asphalt layers 104, 106. The fire retardant in the asphalt layers 104, 106 can be in addition to or in place of the fire retardant that is in the polyester fibers or placed on the polyester sheet 102. In this manner, an impact resistant and fire retardant shingle can be formed having a polyester sheet substrate layer. 

What is claimed is:
 1. A method of making a roofing shingle comprising: forming a non-woven polyester sheet having a mass of at least 65 grams per square meter; coating said non-woven polyester sheet with a fire retardant; heating asphalt to a liquid state; applying said asphalt in said liquid state to a first side of said polyester sheet and to a second side of said polyester sheet; allowing said asphalt to cool in ambient air.
 2. The method of claim 1 further comprising: mixing additives with said asphalt in said liquid state to reduce the equiviscous temperature of said asphalt.
 3. The method of claim 2 wherein said process of mixing additives comprises mixing napthenic oil with said asphalt.
 4. A method of making an impact resistant roofing shingle comprising: forming a porous polyester sheet having a mass of at least 65 grams per square meter that is made from a plurality of extruded viscoelastic polyester fibers that are entangled using a needle punch process and fused together using heat and pressure; heating asphalt to a liquid state to create liquid asphalt; mixing a fire retardant with said liquid asphalt to form a fire retardant asphalt; applying said fire retardant asphalt to both a top surface and a bottom surface of said porous polyester sheet; applying granules and fines to said fire retardant asphalt to form a shingle material.
 5. The method of claim 4 wherein said step of mixing a fire retardant with said liquid asphalt comprises mixing ammonium sulfate with said liquid asphalt.
 6. The method of claim 5 further comprising: mixing additives with said liquid asphalt to reduce the equiviscous temperature and decrease viscosity of said asphalt.
 7. The method of claim 6 wherein said process of mixing additives to said liquid asphalt comprises mixing napthenic oil with said liquid asphalt.
 8. A method of making an impact resistant and fire retardant roofing material comprising: mixing polyester and a fire retardant in a dry state; heating said polyester and said fire retardant to form a fire retardant and polyester liquid; extruding said fire retardant polyester liquid to form a plurality of extruded fire retardant polyester fibers; entangling the resulting fire retardant polyester fibers through a needle punch process to create at least one layer of intertwined, non-woven, polyester fibers; calendering said at least one layer of intertwined, non-woven, polyester layer by passing said polyester layer through a heated calender roll to form a porous fire retardant polyester sheet; heating asphalt to a liquid state to create liquid asphalt; applying said liquid asphalt to both a top surface and a bottom surface of said porous, fire retardant polyester sheet; applying granules and fines to said asphalt to form said impact resistant roofing material.
 9. The method of claim 8 further comprising: coating said porous fire retardant polyester sheet with a fire retardant material.
 10. The method of claim 8 further comprising: mixing a fire retardant with said liquid asphalt.
 11. The method of claim 8 further comprising: mixing additives with said liquid asphalt to lower the softening point temperature and decrease viscosity of said liquid asphalt.
 12. A system for making an impact resistant polyester roofing shingle comprising: a non-woven, two layer polyester sheet that is made from a plurality of extruded polyester fibers that are entangled in a needle punch process and fused together by passing said polyester layer through heated calender rolls to form a porous polyester sheet; a heated asphalt mixer that mixes a fire retardant material with a heated, liquid asphalt to create a fire retardant liquid asphalt; coaters that coat said non-woven, two layer polyester sheet with said fire retardant liquid asphalt on both a top surface and a bottom surface of said non-woven, two layer polyester sheet to form an asphalt coated polyester sheet; a granule applicator that applies granules to said asphalt coated polyester sheet; a fines applicator that applies fines to said asphalt coated polyester sheet.
 13. The system of claim 12 wherein said heated asphalt mixer mixes at least one additive to lower the softening point temperature and decrease the viscosity of said asphalt.
 14. The system of claim 13 wherein said additive is napthenic oil.
 15. The system of claim 12 wherein said fire retardant is ammonium sulfate.
 16. A system for making an impact resistant polyester roofing shingle material comprising: a mixer that mixes polyester with a fire retardant to form a fire retardant, polyester dry mix; an extruder that heats said fire retardant, polyester dry mix to form a fire retardant, polyester liquid; a metering pump and spinneret system that extrudes said fire retardant, polyester liquid to form a plurality of extruded fire retardant polyester fibers; a needle machine that entangles said fire retardant polyester fibers to create at least one layer of entangled, non-woven, polyester fibers; a calender roll process that compresses and heats said layer of entangled, non-woven, polyester fibers to form a porous polyester sheet; coaters that coat said porous polyester sheet with liquid asphalt.
 17. The system of claim 16 further comprising: a heated asphalt mixer that mixes at least one additive with said liquid asphalt to lower the softening point temperature and decrease the viscosity of said liquid asphalt. 